title: Improved detection of di-peptides by liquid chromatography-tandem mass spectrometry with 2,4,6-trinitrobenzene sulfonate conversion.
abstract: Highly sensitive detection of small peptides at the pM level was achieved by liquid chromatography-multiple reaction monitoring-tandem mass spectrometry (LC-MRM-MS/MS) in combination with the 2,4,6-trinitrobenzene sulfonate (TNBS) conversion technique. Six di-peptides having Tyr at the C-terminal (i.e., Gly-Tyr, Val-Tyr, Met-Tyr, Glu-Tyr, Lys-Tyr and His-Tyr) were subjected to the TNBS-MRM analysis in this study. The TNBS conversion conditions of pH 8.0, 30 °C and 60-min incubation enabled the di-peptides to be successfully converted to a trinitrophenyl (TNP) form with the mass increment of +212 Da. The proposed TNBS-MRM method enabled di-peptide detection that was highly improved by a factor of 3-55 in signal-to-noise ratio due to increased hydrophobicity by the induced TNP moiety. The method also permitted highly sensitive detection of di-peptides with a detection limit of >54 pM (>1.35 fmol/injection), achieving high reproducibility (<5% coefficient of variation) and rapidity (<30 min) by LC-MRM-MS/MS.
authors.affiliation: Division of Bioscience and Bioenvironmental Sciences, Faculty of Agriculture, Graduate School of Kyushu University.
authors.forename: Eduardo M N
authors.initials: EM
authors.lastname: Nakashima
authors.forename: Hu-Qiang
authors.initials: HQ
authors.lastname: Qing
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Tanaka
authors.forename: Toshiro
authors.initials: T
authors.lastname: Matsui
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D004151:Dipeptides / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D016014:Linear Models; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014302:Trinitrobenzenesulfonic Acid / Q000737:chemistry*
chemical_list: D004151:Dipeptides; D014302:Trinitrobenzenesulfonic Acid